The recent technology allows image data to be shared among a plurality of remotely located sites to facilitate communication among the plurality of sites. For example, Japanese Patent Application Publication No. 2005-203886 describes a system, which includes two projectors that are located at different places, and a server that transmits an image to each of the projectors for projection onto a screen through each projector. Each projector captures an image drawn onto the whiteboard, and transmits the captured image to the server. The server combines an original image with the captured image received from the projector, and sends the combined image to another projector for projection onto the screen through another projector.
In the system described in Japanese Patent Application Publication No. 2005-203886, projection of the combined image onto the screen is interrupted at a predetermined interval as the system needs to capture the image drawn onto the whiteboard to generate the combined image for projection.